When was the remote island first inhabited, what did the gigantic stone statues represent and how did ancient islanders move them?
These questions fascinated archaeology professors Carl Lipo of California State University, Long Beach (CSULB) and Terry Hunt of the University of Hawai’i at Manoa. After 10 years of research, Hunt and Lipo published their investigations of Rapa Nui’s civilization in the book The Statues That Walked, which led to the cover story by author Hannah Bloch in the July issue of National Geographic magazine and a Nova/National Geographic television documentary scheduled to air in November.
“Islands are well known as great laboratories for studying how evolution shapes change,” Lipo said. “In the case of Easter Island, we have a really remote place that is completely isolated from the rest of the world. Once people arrive on the island, they’re subject to the limits of whatever the island has. Leaving the island to get some missing resources simply isn’t possible when the nearest bit of land is more than 1,500 miles away by open ocean. Yet, here on Easter Island, we have some of the greatest examples of art and ingenuity in the prehistoric world. This apparent paradox really intrigued me: why would people in this place, of any place in the world, have made and transported nearly 1,000 multi-ton statues? I just had to go there to figure out why.”
Lipo’s and Hunt’s views take a decidedly different direction than previous researchers and are generating commentary in the archaeology community. Rapa Nui once contained lush forests and later experienced an ecological and social collapse, but Lipo and Hunt discovered strong evidence that the destruction was largely the result of rats that came aboard Polynesian settlers’ boats rather than from inhabitants overcutting trees. And, over time, contact with Europeans brought disease and mistreatment to natives, both of which exacerbated the island’s downfall.
“What surprises me about the archaeological record of Easter Island is how poorly known it is,” Lipo said. “Despite more than 100 years of research, much of what we think we know is simply drawn from stories rather than direct observation. Researchers have been blinded by an account that derives from the earliest European visitors in the 18th Century who moralized that prehistoric people must have squandered their resources since the island has large statues but almost no resources. As it turns out, there really was never much in the way of a bountiful set of resources on the island, yet the Rapanui were able to build these statues. What this implies is that our sense that the island represents a destroyed environment is incorrect– the island was made into a productive place by the actions of the Rapanui.”
Another key finding is that island residents likely moved moai statues by a back-and-forth “walking” motion rather than on tree trunk rollers as other scientists proposed. “Oral traditions recorded as early as the 1880s mention that the prehistoric statues ‘walked,’ but most researchers have assumed that this line of evidence is simply a fanciful story,” Lipo explained.
“My colleague, Sergio Rapu, a native Rapanui– the name for the people who live on Easter Island– had studied statues all his life and convincingly argued that these stories were more than just a fable,” Lipo continued. “As we surveyed on the island, he pointed out various features of statues that made no sense if one was going to just put them on rollers or a sledge and drag them. So, with Terry Hunt, we began to study the moai carefully and observing how the ones that were scattered across the landscape before they reached the end of their journey were shaped, how they broke and how they fell over.
“What we found is that the statues found in transport along prehistoric roads have features that could only be explained if the statues were standing and being moved before falling over,” he said. “We then became intrigued in understanding the physics of how this could be so. Our studies of how the statue leaned forward and, when rocked back and forth, would roll across its front edge to minimize friction led us to create the five-ton replica of a road moai and actually try it out. To our great amazement, it worked– the statue walked!”
The forthcoming Nova/National Geographic TV episode focuses on their movement research using the replica moai, funded by National Geographic’s Expeditions Council.
It was a concept that made sense, according to Lipo. “When we move a refrigerator, we do not lay it down on its back and then push it across the kitchen on wheels. Instead, we rock it back and forth and shuffle it from one side of the kitchen to the other. In this way, one person can move a giant refrigerator. The people of Easter Island used this idea but took it to the next level. Like a refrigerator they rock the statue back and forth, but then also shape the statue so that it takes advantage of the movement.”
Modern island dwellers shared ancestral Rapanui stories with Lipo and Hunt that corroborated this moai transportation idea. “They even have a word for this kind of motion– neke-neke– which means ‘shuffle forward on your feet in a twisting motion.’ Individuals have told us that their grandmothers used to sing a song about the walking moai and do the neke-neke motion. So for them, it’s an obvious link to their traditional beliefs.”
Lipo said he and Hunt have much more to learn about the Rapanui. “Their management of the land supported statue construction in a way that was sustainable for more than 500 years,” said Lipo. “Assumptions about ecological catastrophe are simply unwarranted. Thus, we need to examine the island’s archaeology in light of this understanding and to look directly at the record to understand how they were able to achieve what they did. This will take a lot of additional field work.”